Potential role of Angiotensin-(1-7) in the improvement of vascular insulin sensitivity after a bout of exercise.

NEW FINDINGS: What is the central question of this study? A bout of exercise increases subsequent insulin-stimulated vasodilation; however, the mechanisms remain to be elucidated. A potential role for Angiotensin-(1-7), a vasoactive peptide of the Renin-Angiotensin System, in this effect has not been previously reported. What is the main finding and its importance? We show that Angiotensin-(1-7) through Mas receptor participates in enhanced insulin-induced vasorelaxation after exercise in healthy rats. This new potential role of Angiotensin-(1-7) could help to understand how physical activity improves vascular insulin sensitivity in normal and insulin resistant states.

ABSTRACT: Exercise increases insulin-stimulated vasodilation, but the mechanisms involved are unclear. This study was performed to investigate the possible involvement of Angiotensin-(1-7) (Ang-(1-7)), a vasoactive peptide of the Renin-Angiotensin System (RAS), in enhanced vascular insulin sensitivity after a bout of exercise. Male Wistar rats were subjected to swimming for 2.5 h. After exercise, carbachol- or insulin-induced relaxation in aorta was assessed. Prior exercise improved insulin-stimulated vasorelaxation; however, this insulin-sensitizing effect was prevented by the selective Mas receptor (MasR) (Ang-(1-7) receptor) antagonist A779. Carbachol-mediated vascular relaxation was not modified by exercise. These results suggest that Ang-(1-7) acting through MasR participates in the enhancement of vascular insulin sensitivity after an exercise session. This new potential role of Ang-(1-7) could help to understand how exercise improves vascular insulin sensitivity in normal and insulin resistant states. This article is protected by copyright. All rights reserved.